The invention relates to a circuit design for patch panels and particularly a circuit design for a dual-side circuit board coupled with jacks and Insulation Displacement Connectors (IDCs) to conform to Category 6 (Cat.6) communication standard.
In order to respond the growing applications of high speed networks post-Ethernet 100 MHz networks, working groups in Telecommunications Industry Associations (TIA) of U.S.A. has developed and announced an Enhanced Cat. 6 standard based on the wiring system of Category 5 (Cat. 5) 100 MHZ (titled: TSB-67). The Cat. 6 standard expands from 100 MHZ of Cat. 5 to 250 MHZ. In 1998 IEEE made a request to TIA and ISO on new wiring system specifications, performance requirements must be at least 25% more than the accumulated power fading cross-talk ratio (ACR). Hence test frequency for Cat. 6 performance has even reached 350 MHZ. The major difference between the Cat. 6 standard and the Cat. 5 standard is that Cat. 6 standard has improved performance in cross talk interference and return loss. In the new generation of full duplex high speed network applications, improved performance on return loss is very important. Cross talk is a critical factor for implementing wide band applications. Although 00 MHZ is still the mainstream of the present network installations, Cat. 6 standard is a more desirable protocol to meet future requirements.
The standard set forth above is not only targeted on high speed communication cables, in order to maintain same high speed transmission performance in the high speed communication networks, the peripheral devices related to the high speed communication cables also should have matching designs, especially telecommunication connection elements such as RJ-45 type plug and jack. The RJ-45 connectors (including plug and jack) used in high speed communication networks generally are 8P8C type. 8P means eight positions, and 8C means eight gold plated contacts. However, in practical applications, only two pairs of lines are used. Other two pairs of lines may be used for other devices such as telephones and facsimile machines. There are two types of connector specifications according to EIA/TIA definitions, i.e. EIA/TIA-568A and EIA/TIA-568B. EIA/TIA-568A is obsolete now. EIA/TIA-568B is continuously being used. Its pin positions 1-8 are arranged sequentially and are connected respectively with four pairs of twisted communication lines (such as Unshielded Twisted Pair or Shielded Twisted Pair). The pin positions are respectively marked by T (Tip terminal) and R (Ring terminal) according to different current directions. The general standard communication cable lines have four twisted pairs twisted in pairs and marked by different colors. The colors of the cable lines are blue/white-blue, orange/white-orange, green/white-green, and brown/white-brown.
In the circuits of these communication connecting devices, to include capacitors or induction effect to reduce cross-talk and improve return-loss is a well-known technique. For instance, U.S. Pat. No. 5,864,089 to Rainal, entitled: xe2x80x9cLow-crosstalk modular electrical connector assemblyxe2x80x9d, and U.S. Pat. No. 5,435,752 to John Siemon et al, entitled: xe2x80x9cElectrically Balanced Connector Assemblyxe2x80x9d disclose circuit structures that have circuit conductors laid on the circuit board surface equivalent to capacitors or inductors. They mainly deploy selected circuit conductors on the surface of two sides of the circuit board to form capacitors, or lay circuit conductors adjacent to each other at a selected interval on the surface of the same side of the circuit board to generate induction effect. While they can reduce cross-talk and improve return-loss to some degree, they still cannot meet the critical requirements of Cat. 6 standard.
The primary object of the invention is to provide a circuit board conforming to Cat. 6 standard to improve cross-talk and return-loss of jacks mounted to the circuit board.
Another object of the invention is to provide a circuit board that has a simple circuit design and particularly a circuit board coupled with jacks and IDCs.
The circuit board coupled with jacks according to the invention mainly is targeted on the improvement of the pair 1 conductors and pair 3 conductors of the jack and IDC. The improvements include: the main conductors between the jack and IDC are laid respectively on two sides of the circuit board and have enlarged areas such that a capacitor structure is formed between the pair 1 conductors and the pair 3 conductors. In the vicinity of the juncture of the IDC and main conductor, the ends of the pair 1 and pair 3 conductors are extended and lengthened to allow the pair 1 and pair 3 conductors forming a TR (or TT, RR) layout related to each other, and in the vicinity of the juncture of the jack and main conductor, the ends of the pair 1 and pair 3 conductors are extended and lengthened to allow the pair 1 and pair 3 conductors forming a TT or RR (or TT or RR for the IDC end, and TR for the jack end) layout, thereby to generate induction effect. By means of the balanced effect resulting from multiple levels of capacitance and inductance, cross-talk interference can be reduced to meet the requirements of Cat. 6 standard.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.